Update translations before v2023.3 regression testing

[matthew-white]

This PR updates translations to the latest, making progress on #759. I'll pull translations again shortly before release. Note that we have two messages that have yet to reach Transifex (one each in #809 and #811). However, that shouldn't be an issue: those messages are purely additive, and we'll be able to pull any translations for them later.

What has been done to verify that this works as intended?

The only thing that should have changed in this PR is Transifex JSON files in transifex/ and the autogenerated <i18n> blocks. The QA team will verify translations during regression testing. Italian is currently 100% translated. 🎉

Before submitting this PR, please make sure you have:

• run npm run test and npm run lint and confirmed all checks still pass OR confirm CircleCI build passes
• verified that any code or assets from external sources are properly credited in comments or that everything is internally sourced